Rich Kane/US PresswireGiants safety Kenny Phillips is out for the year, but the team is optimistic he'll be able to contribute in future seasons.When Giants safety Kenny Phillips was placed on injured reserve with a left knee injury this afternoon, the diagnosis the team revealed was patellofemoral arthritis -- a condition in which the the cartilage has worn down behind the kneecap, where it sits against the femur.

Since that is a joint that carries a lot of stress, it is a challenging condition for a football player and can result in lingering pain and discomfort. But the long-term prospects of playing with the condition vary widely depending on its severity in a player, which can only be determined by the doctors who examined him.

"It's premature to say it's career-ending unless you had the information (for the player)," said one physician and sports medicine expert, who asked to remain anonymous because they have not examined Phillips and do not know the specifics of his case. "It's a challenging problem to deal with. It's not something that’s going to likely go away; it's something he's going to have to deal with. But career-ending is kind of hard -- if it's significant, it can be career-threatening."

The doctor stressed there is "a lot of variation" in cases of patellofemoral arthritis, depending on how large the defect in the cartilage is.

For less severe conditions, the problem can be managed -- like the Giants had been doing with Phillips since the issue first came up in training camp -- by trying injections of anti-inflammatories or lubricants, rest to see if the swelling in the joint quiets down or a brace to control the movement of the kneecap. If the knee continues to swell or the condition is more severe, that's when surgery is considered.

This seems to be in line with Phillips' timeline. He tried to manage the condition for several weeks, but after an MRI Wednesday revealed it had worsened, was placed on IR and will consider surgery. According to a source, while a treatment plan for Phillips has not yet been decided upon, microfracture surgery has been discussed.

According to the doctor consulted for this article, what microfracture surgery would do is help to regenerate a new lining on the bone. This is achieved by picking at the bone to create small microfractures in the surface, causing it to bleed and stimulating the growth of new cartilage.

"It hopefully regrows some of the cartilage so he can go through his career," the doctor said. "It's never as good as the original, but it is kind of something to buy some time, get a lining on it."

That objective seems to jibe with the comments made by the Giants, who expressed disappointment over losing Phillips for the year but optimism he will be a contributor for the team in future seasons. Coach Tom Coughlin said in the team's release that Phillips' problem needed to be corrected but "I’m sure he’ll rehab and be back with us in the spring."

Added Phillips: "Longevity is the key, so this is why we are going through with it."

According to the doctor, patellofemoral arthritis could result from a prior instance when the kneecap was dislocated or shifted, a direct blow to the knee or multiple smaller injuries. It's possible, the doctor added, that his condition is not full-blown arthritis and has started as a break in the cartilage.

Phillips said he is unsure exactly when the condition first developed. He noticed swelling in his knee at some point during training camp, but chalked it up to the usual nicks and bruises.

Without the specifics, a long-term prognosis is difficult to determine. The bottom line, though, is that while patellofemoral arthritis can present a challenging road for an NFL player, the road has not necessarily reached a dead end.

"It definitely can be very troublesome; it's definitely not a good injury to have," the doctor said. "But it depends on how big the break in the cartilage is, where on the weight-bearing surface, things like that."